He suggested that perhaps the ring was made by millions of bees or insects, although he says, “I’ve never heard of insects behaving in this way before, so if this is the explanation, it’s a real-life X-File.”

But there may be a simpler explanation - that the ring was simply caused by lighting a ring shaped fire.

According to NBC, in the US they can be attributed to, "a homemade trash-can smoke ring launcher, or a hippie-dippie apparatus."